Drag-offset for sawmill-carriages.



R SMVMILL CAHRIAGESB 2 SHEETSMSHEET I.

SLE) MAY 7, 1917.

APPHCATIOH 0. KREBS. DRAG GFFSz'Y FOR SMJMILL CHRIAGES.

AP'E'HCAFIUN FILED HAY 7, WH-

CTI

OLIVER IVI. KREBS, OF MEMPHIS, TENNESSEE, ASSIGNOR TO THE NHELANDCGIVIEANY,

OF CHATTANOOGA, TENNESSEE, A CORPORATON OF TENNESSEE.

DRAG-OFFSET FOR SAWMILL-CRRIAGES.

Application filed May 7, 1917.

To all whom t may concern:

Be it known that OLIVER M. Knees, a citizen of the United States,residing at Memphis, in the county of Shelby and State of Tennessee,have invented certain neiy and useful Improvements in Di'ag-Uil'sets forSawmill-Carriages, of Which the following is a speciiieation.

My invention relates to an improvement in drag offsets fo'r saw-infillcarriages.

As is Well understood, the function of a carriage-offset is to cause thesaw-mill can riage frame to slide laterally on the axles, so that thelog carried by the iframe will clear the savv as the carriage returns tothe log` deck, and then as the carriage moves 'forward With the cuttingof the next board, the offset must lirst return the carriage tramelaterally on its axle up to the saw line7 after yvhich the.carriage-moves down the track past the saw, and the board is sawed offthe log.

This is accomplished at present by means of a drag, which restsrictionall-y upon one of the rails, and with. respect to ,which theearriageirame has a. limited travel before the frictional resistance otthe drag upon the rail is overcome by` the carriage-frame striking thedrag and carrying it along, the eifect of which, through the system otlevers, is to cause the automatic lateral shift'- ing of the saw-millcarriage frame upon the axles, and, as the carriage reverses-in otherWords Whether moving in one direction or the other-the drag Will remainstill on the rail until the carriage has traveled along the track asicaras the guide which incloses the upper end of the. drag Will allow",and it is when the drag is stationary, and the carriage is moving, thatthe offset takes place.

The foregoing is old and common practice.

A defect in the present system as above outlined, is that il thecarriage is traveling in either direction at at'air speed, it the Sawyeror one who operates the carriage, suddenly stops the carriage, thetendency oi the drag is to continue to travel on, due to its momentum,thereby causing the carriage to a-utoinaticallyV oset laterally at theWrong time.

The object of my present invention is to eftectually overcome thistendency, and it consists in abend friction applied to one etSpecification of Letters Patent.

Patented Nov. 2217, 7..

Serial No. 166,944.

the axles, and connected with `the drag, thereby preventing` orovercoming this momentumof the drag in the event of a sudden stop ot'the carriage.

ln the accompanying drawings z- Figure l is a plan vieiv;

Fig. 2 is a side elevation;

Fig. 3 is a view in perspective oli the parts dismembered; and

Fig. el is an enlarged sectional detail.

A, is the carriageeframe; l, l, are the axles; 2, 2, indicate thegrooved Wheels on the track 3; 4 indicates the drag which by gravityrests upon thc rail 8, as clearly illustrated in Fig. 2 with which it isin frictional engagement. The upper end 5 of the drag is confinedslidingly in the. guide 6 secured to the side of the carriaged'frame,and which is preferably inclined as shown in Fig. l, to allow for thelateral movement of the frame in the automatic shifting with respectthereto.

The levers 7, 7, are pivotcd to the crossbars 8 on the carriage-trame,as shown at il, and are also pivotally Connected with the sleeves 10confined between collars` ll, ll, on the end axles; and connecting-bars12, l2, extend from the long arms of the levers 7 to the drag el.

A friction 13, constructed in any convenient. manner, but convenientlyas illustrated A in Fig. 3, embraces a drum 14 secured on one'materially assists the drag to do its Work.

it connecting-rod 16 extends from the band friction to the drag 4, -andthis may be lengthened or shortened through any convenient means, suolias a turn-buckle 17 to regulate the adjustment as to length.

From the foregoing construction it will be understooddhat, by means ofthe band friction, any vtenlency oit the drag to continue on7 after asudden stop of the saw-mill carriage, which might otherwisew-andreduently has-occurred until the end 5 reached the opposite end or' 'theguide 6, is eilectually resisted by the rictional contact of the band 13upon the drum 14, thi 1s absolutely preventing a yprenfiature lateralshifting or oilset of the saw-mill carriage, which is 'the purpose of mypresent invention.

While l have described a Way of Ydoing this, it is obvious that otherschemes might be devised to accomplish the same thing, the gist of myinvention being to cause the drag to stop when the carriage stops, orWith the carriage, instead of Continuing on by m0- mentum at a time whenthe effect would' be to cause a lateral shifting or otl'setting of thesawmill carriage at anlinopportune time in the sawing operation. i',

- The offsetting cannot take'place' until the axle reverses. As soon asthe carriage starts I back, the olset begins, which cannot take platebefore the carriage starts to reverse.

I claim:

l. The combination with a laterally-shiftable saw-mill carriageeframe-and a drag adapted to frictionally engage a rail on which the carriagetravels, andin'conned tion with which the carriage-frame. has a certainamount of independent movement,

- and means connected'with the saw-mill can riage frame and drag forcausing the automatic lateral shift of the carriage as the frame movesindependently of thev drag, of means connected with the drag forpreventing the drag from moving on by momentum, independently of thecarriage frame,

when the latter-,is suddenly stopped.

9.. r)She combination with a laterally-shift ble. saw-mill carriaaerameand a drag adapted to friction-ally mgage a rail von which the carriagetravels, and in connection with which the carriage-frame has a certainamount of independerlt A'movement and means connected with' the saw-millcarriageframe and drag for causing the automatic lateral shift of thecarriage as the frame moves independently of the drag, of meansconnected -With the drag, carriage and axle whereby to prevent the dragfrom moving on by momentum, independently of the carriage lframe, whenthe latter is Suddenly stopped. ,3. The combination with alaterally-'shift` able saw-mill carriage-frame and a drag adapted torictionally engage a rail on which the carriage travels, and inconnection with which the'carriagedrame has a certain amount ofindependent movement, and ymeans connected with the saw-millearriage-frame and drag for causing the automatic lateral shift ofthecarriage as the frame moves independently of the drag, of meansconnected with the drag for prevent ing the drag from moving on bymomentum, independently of .the carriage frame, when the latter issuddenly stopped, said means comprising a friction connected with oneofv latter is suddenly stopped, said means com-- prising a friction bandconnected with one of the axles of the carriage and with the drag, andmeans for regulating the tension 0f said friction means.

5. An offsetting mechanism for saw-mill carriages comprising a. dragwith which the carriage has limited endwise movement, and meansconnected Withthe drag, said means frictionally connected With one ofthe axles of the carriage, W11ich\ efectually prevents offsetting of thecarriage until the axle reverses.

In testimony whereof I affix my signature.

` OLIVER M. KREBS.

